The "Research Resource for Genetics of Families with Multiple Autoimmune Diseases" (hereafter referred to as the Resource) will be a repository of genetic and clinical data and materials collected from families with multiple autoimmune diseases. The goal of the Resource is to collect and characterize multiplex (two or more individuals affected individuals) families affected by two or more distinct autoimmune diseases. This facility will provide research materials to the scientific community. Upon approval of research applications, researchers will be supplied with subject DNA, clinical, demographic and laboratory data. Subject's materials will be given anonymous identifiers to ensure the privacy of Resource participants. This proposal consists of nine specific objectives: 1) to identify and compile a list of suitable families with multiple autoimmune diseases; 2) to establish criteria for study entry and recruitment procedures; 3) to establish a comprehensive database for the storage and analysis of clinical and genetic data; 4) to collect a minimum of 400 multiplex families that have two or more individuals affected with two or more of five major autoimmune diseases; 5) to establish a centralized biorepository for the storage of DNA, plasma, and frozen PBL/cell lines on all appropriate family members whether affected or unaffected; 6) to perform limited genotyping analysis on all subjects to confirm the nature of the genetic relationships within these families; 7) to perform limited HLA typing on all appropriate family members whether affected or unaffected; 8) to establish a mechanism for the distribution of clinical data and biological materials to investigators who wish to utilize this resource for research purposes; and 9) to provide for annual follow up of all individuals in the study, for the purpose of identifying the new appearance of autoimmune disorders in these families.